ZusammenfassungDie posterolaterale Instabilität des Kniegelenks tritt typischerweise bei Verletzungen der posterolateralen Gelenkecke oder bei zusätzlichen Kombinationsverletzungen mit Beteiligung ...des vorderen und hinteren Kreuzbands auf. Neben zahlreichen, kleineren anatomischen Strukturen sind an erster Stelle das laterale Kollateralband (LCL), der M. popliteus mit dessen Sehne sowie das popliteofibulare Band (PFL) zu nennen, welche bildgebend mittels Magnetresonanztomographie (MRT) in der Regel gut zu beurteilen sind. Kleinere Strukturen wie das Lig. arcuatum und das Lig. fabellofibulare sind nicht regelhaft abzugrenzen, und sind von geringerer Bedeutung für die Entwicklung einer posterolateralen Rotationsinstabilität. Übersehene Verletzungen der posterolateralen Gelenkecke begünstigen jene Instabilität mit der Komplikation von insuffizienten Bandrekonstruktionen und dem frühen Auftreten einer posttraumatischen Arthrose. Die Kenntnis der MRT-Morphologie der beteiligten anatomischen Strukturen unter Berücksichtigung der biomechanischen Bedeutung ist entscheidend, um die entsprechenden bildgebenden Befunde zu erkennen und zu benennen.
The optimal design, sizing and operation of building energy systems is a complex problem due to the variety of available generation and storage devices as well as the high-resolution input data ...required for considering seasonal and intraday fluctuations in the thermal and electrical loads as well as renewable supply. A common measure to reduce the problem's size and complexity is to cluster the demands into representative periods. There exist many different algorithms for the clustering, but to the best of our knowledge, no comparison has been made that illustrates which algorithms are the most appropriate for such problems.
Therefore, this paper compares six aggregation methods for reducing full year input data to typical demand days for energy system synthesis. We consider seasonal and monthly classification as well as sophisticated clustering methods such as k-centers, k-means, k-medians and k-medoids for aggregating the heat and electricity demand as well as solar irradiation onto the roof of a single-family house and an apartment building.
The results show that all clustering methods are able to determine energy systems that are close to the optimal system, however their demand related costs are approximated best and most reliably with k-medoids.
•Comparison of aggregation algorithms for the selection of typical demand days.•All investigated aggregation methods significantly reduce optimization times.•K-means, seasonal and monthly algorithms are not suitable for fluctuating loads.•K-medoids offers the most reliable clustered load profiles for system optimization.
Existing non-residential buildings account for a significant proportion of the energy consumption of the European building stock. Modernizing these buildings can significantly contribute to declared ...emission reduction targets. Modernization measures are rarely realized in the life cycle of buildings but have long-term effects on their energetic performance. Therefore, it is not only essential to identify future-oriented modernization measures but also to schedule them over the life cycle of a building. For this purpose, we present a mixed-integer linear program that schedules measures for a building energy system including envelope and supply system. The program determines not only the optimal combination of modernization measures but also the respective optimal point of time when each measure shall be realized. A multi-objective optimization is conducted to minimize carbon emissions and net present value. Thermal demand profiles serve as input for the optimization model and are calculated preliminary using dynamic simulations. Constraints and boundary conditions are specified separately for each prospective year of the schedule's time horizon. Results showed that the constitution of a building energy system changes several times throughout a schedule. Determined Pareto-efficient solutions reveal that carbon emissions could be saved more cost-efficiently than with approaches without scheduling.
•Novel approach of optimizing a temporally varying building energy system.•Combination of thermal demand simulations and mixed-integer linear programming.•Regarding different boundary conditions for every considered year inside a MILP.•Application on typical building for prospective scaling on building stocks.
Real energy performances of buildings depend not only on deterministic aspects, such as building physics and HVAC systems, but also on stochastic aspects such as weather and occupants' behavior. ...Typically, occupant behavior is not adequately considered when calculating the expected performance. As a result, field test studies all over Europe have shown discrepancies between real and expected energy performance of buildings. In order to bridge this gap, stochastic occupants' behavior models could be embedded into building energy performance simulation software. In order to make such models, there is a need for a better understanding of occupants' behavior and in particular the reasons of their adjustments of building controls such as window opening, heating set points, etc. The purpose of this paper was to analyze window opening behavior in residential buildings, investigate which drivers lead occupants to interact with windows and how these actions can be modeled. A method to analyze the probability of a state change of the windows, based on logistic regression, was applied to monitored data (measured each minute) from two refurbished demonstration buildings. The weather and the five rooms of the 60 apartments located in the buildings were monitored in terms of air quality and thermal environment (presence of occupants was not monitored) during four years.
The most common driver to open a window was the time of the day, followed by the carbon dioxide concentration. The most common driver to close a window was the daily average outdoor temperature, followed by the time of the day.
•Occupants open and close windows depending on drivers leading them to take action.•Drivers can be identified through logistic regression analysis.•The most common drivers for opening action are: time of the day and CO2 concentration.•The most common drivers for closing action are: outdoor temperature and time of the day.•Thermal comfort and AIQ play a role for occupant behavior in regard to natural ventilation.
District heating is a state of the art technology for efficient supply of heat. Modern 4th generation and 5th generation district heating networks can be used to integrate sources of waste heat, ...which allows efficient operation. The design of such heating networks is subject of many optimization models. Most optimization models focus on energy flows and result in Mixed Integer Linear Programs. This requires simplifications, where temperatures and mass flow rates are neglected or simplified. This work presents a Mixed Integer Quadratically Constrained Program with temperature constraints. A case study is presented, where the integration of low temperature waste heat in a district heating network is optimized. In this case study the positioning of heat pumps at the supply or at the consumers influences network operation. The results show a trade-off between economical and ecological optimal solutions with a range of total annualized costs from 120,000 EUR/a to 307,000 EUR/a and a range of CO2-Emissions from 193 t/a to 605 t/a. Furthermore, the influence of design decisions on the optimal operation is demonstrated. All in all, the quadratic model formulation stresses the influence of temperatures on the optimization outcome and offers pareto optimal solutions for the design of the presented case study.
•Low temperature district heating allows to integrate waste heat sources.•Design optimization of district heating depends on temperatures of all parties.•MIQCP formulation of design optimization allows to regard temperatures.•Temperature sensitive Heat Pump positioning in district heating is demonstrated.
Aims
To investigate the efficacy and safety of alirocumab in participants with type 2 (T2D) or type 1 diabetes (T1D) treated with insulin who have elevated LDL cholesterol levels despite maximally ...tolerated statin therapy.
Methods
Participants at high cardiovascular risk with T2D (n = 441) or T1D (n = 76) and LDL cholesterol levels ≥1.8 mmol/L (≥70 mg/dL) were randomized 2:1 to alirocumab:placebo administered subcutaneously every 2 weeks, for 24 weeks' double‐blind treatment. Alirocumab‐treated participants received 75 mg every 2 weeks, with blinded dose increase to 150 mg every 2 weeks at week 12 if week 8 LDL cholesterol levels were ≥1.8 mmol/L. Primary endpoints were percentage change in calculated LDL cholesterol from baseline to week 24, and safety assessments.
Results
Alirocumab reduced LDL cholesterol from baseline to week 24 by a mean ± standard error of 49.0% ± 2.7% and 47.8% ± 6.5% vs placebo (both P < .0001) in participants with T2D and T1D, respectively. Significant reductions were observed in non‐HDL cholesterol (P < .0001), apolipoprotein B (P < .0001) and lipoprotein (a) (P ≤ .0039). At week 24, 76.4% and 70.2% of the alirocumab group achieved LDL cholesterol <1.8 mmol/L in the T2D and T1D populations (P < .0001), respectively. Glycated haemoglobin and fasting plasma glucose levels remained stable for the study duration. Treatment‐emergent adverse events were observed in 64.5% of alirocumab‐ vs 64.1% of placebo‐treated individuals (overall population).
Conclusions
Alirocumab produced significant LDL cholesterol reductions in participants with insulin‐treated diabetes regardless of diabetes type, and was generally well tolerated. Concomitant administration of alirocumab and insulin did not raise any safety concerns (NCT02585778).
Please click on this video link to learn more about this study.
How sudden is sudden cardiac death? MÜLLER, Dirk; AGRAWAL, Rahul; ARNTZ, Hans-Richard
Circulation (New York, N.Y.),
09/2006, Letnik:
114, Številka:
11
Journal Article
Recenzirano
Out-of-hospital sudden cardiac death (SCD) is a frequent cause of death. Survival rates remain low despite increasing efforts in medical care. Better understanding of the circumstances of SCD could ...be helpful in developing preventive measures and facilitating proper reactions to such a pending event.
Information on cases of out-of-hospital SCD was collected in the Berlin, Germany, emergency medical system via a questionnaire. Bystander interviews were performed by the emergency physician on scene immediately after declaration of death or return of circulation. Of 5831 rescue missions, 406 involved patients with presumed cardiac arrest. Sixty-six percent had a known cardiac disease. In 72%, the arrest occurred at home, and in 67%, it occurred in the presence of an eyewitness. Information on symptoms immediately preceding the arrest was available in 80% (n = 323) of all 406 patients and in 274 of those with witnessed arrest. Symptoms were identical in the 2 groups. Typical angina was present for a median of 120 minutes in 25% of the 274 patients with witnessed arrest and in 33% with a symptom duration of less than 1 hour.
SCD occurs most often at home in the presence of relatives and after a longer period of typical warning symptoms. Although the much-hailed use of public access defibrillation is supported by several studies, the present results raise the question of whether educational measures and targeted educational programs tailored for patients at risk and their relatives should have a higher priority.
•A novel method for an integrated, sustainable design of heat pump systems.•Multi-level optimization of refrigerant, flowsheet, controller, and system components.•Multi-domain optimization of cost, ...emissions, and occupant comfort.•Dynamic simulation model covering annual demand.•Application of superstructure based two-stage optimization using a surrogate-based algorithm.
Aiming for a sustainable building stock, air-source heat pump systems are a key technology. In residential application, heat pump systems typically consist of a heat pump, an auxiliary heater, two thermal storages (for space heating and domestic hot water), and a system controller. Compared to conventional technologies, the efficiency of a heat pump system is highly dependent on it’s design, (component sizes, flowsheet, and refrigerant choice) and its operating conditions, particularly part load and temperature levels. While design strategies exist on different domains in the literature, there is no integrated strategy to optimally design heat pumps systems. In this work, we use process intensification to consider the heat pump system design and operation simultaneously. Formulating the intensification process leads to a two-stage MINLP optimization problem with multiple objectives: Costs and emissions. In the first stage, the design is optimized in an annual dynamic building performance simulation using a surrogate-based optimization procedure. Then, using the same dynamic simulation models, the system controller is optimized in the second stage using a Genetic Algorithm. Our results underline the necessity for integrated optimization process. The integrated process can decrease annualized costs up to 36% and emissions up to 51% compared to standard design procedures.
Aim
To compare alirocumab, a proprotein convertase subtilisin‐kexin type 9 inhibitor, with usual care (UC) in individuals with type 2 diabetes (T2DM) and mixed dyslipidaemia not optimally managed by ...maximally tolerated statins in the ODYSSEY DM‐DYSLIPIDEMIA trial (NCT02642159).
Materials and Methods
The UC options (no additional lipid‐lowering therapy; fenofibrate; ezetimibe; omega‐3 fatty acid; nicotinic acid) were selected prior to stratified randomization to open‐label alirocumab 75 mg every 2 weeks (with increase to 150 mg every 2 weeks at week 12 if week 8 non‐HDL cholesterol concentration was ≥2.59 mmol/L 100 mg/dL) or UC for 24 weeks. The primary efficacy endpoint was percentage change in non‐HDL cholesterol from baseline to week 24.
Results
The randomized population comprised 413 individuals (intention‐to‐treat population, n = 409; safety population, n = 412). At week 24, the mean non‐HDL cholesterol reductions were superior with alirocumab (−32.5% difference vs UC, 97.5% confidence interval −38.1 to −27.0; P < .0001). Overall, 63.6% of alirocumab‐treated individuals were maintained on 75 mg every 2 weeks. Alirocumab also reduced LDL cholesterol (−43.0%), apolipoprotein B (−32.3%), total cholesterol (−24.6%) and LDL particle number (−37.8%) at week 24 vs UC (all P < .0001). Consistent with the overall trial comparison, alirocumab reduced non‐HDL cholesterol to a greater degree within each UC stratum at week 24. The incidence of treatment‐emergent adverse events was 68.4% (alirocumab) and 66.4% (UC). No clinically meaningful effect on glycated haemoglobin, or change in number of glucose‐lowering agents, was seen.
Conclusions
In individuals with T2DM and mixed dyslipidaemia on maximally tolerated statin, alirocumab showed superiority to UC in non‐HDL cholesterol reduction and was generally well tolerated.
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